A Game Over file is a file which uses the namesake card Game Over -- https://alteil-login.apocoplay.com/cardDB/detail.php?id=1665. The basic gameplan is to develop a better field on your side so the opponent has to compensate by increasing their field, making them extend more into the Game Over. While it will set units to 0 HP and SP to 0 on both sides, the key is to lessen the impact better than the opponent. There are two parts to it -- unit selection and timing.

What are some good units for it?Units that are good for Game Over files are grimmune or have an ability that saves other units upon close. They are units that are going to either hang out on the field after a Game Over or help other units hang out. Some examples:

In addition, you want to time your Game Over to put yourself in a better position than your opponent. Consider these signals to look out for if your considering a Game Over:-Your opponent has no closed units-You have no open units and some closed units-You have some grimmune units or some recovery-on-close units and some closed units-You have a few excess SP you can put into sphere levels for future units.-Your opponent has units you don't like

Some mids/bigs with Game Over. Opening is 4 Ref > Emerald Buncle, Limier, Mediator, then depending on the matchup you go from there. Shadow Spirit gives some much-needed ranged attack, Fortune shuts down some key opposing units (Dio, EFrog, Undeads, Dilate, etc.), and Garfath gives some non-grim healing. Zangadylan is an optional finisher, mostly for in case of heavy grim bane.

Originally I had a 50-DMG SS in the second slot, but I switched to a 15xLVL SS for BK Rivera matchups.

I've made it up to 1700 RP with this file.

Bad Matchups:Solar Kingdom - Main problem cards are Aliria and Etoile, and to a lesser extent Safiria. Bk Rivera - Ultimately it comes down to if you're able to take down BK early enough. It can be problems if your units are hitting stuff like Dilate or EX Merc Girl.Heavy Grim Bane - Sometimes that Game Over's needed and without it you just get swarmed. Fierte SS - Just since this file has high Sphere level requirements.